N.Vietnam, Ha Tinh Prov., Huong Son Distr., Son Hong Municipality, around point 18є34'06''N, 105є11'40''E. Primary broad-leaved dry closed evergreen forest on very steep mt slopes of Khe Sinh stream canyon and along ridge composed with shale at elev. 600-1100 m a.s.l. near Laotian border. Treelet about 5 m tall. Flowers light green.